Attention from the media and general public has recently soared with regard to forensic chemistry. This rising awareness can be attributed to television shows such as CSI and Forensic Files that have made chemical analysis exciting. By utilizing a forensic-based experiment in an instrumental methods course, student interest in the laboratory can be stimulated. In addition, students will gain valuable experience with an analytical technique(s) that is used in real situations by forensic laboratories.The oldest method of personal identification for forensic purposes is latent fingerprint analysis. The ability to identify suspects from fingerprints left at a crime scene is a result of the arrangement of ridges on the finger pads being unique and permanent to each person (1). Recently, with advances in modern technology, scientists have begun to examine whether information in addition to ridge patterns can be gained from fingerprints. For example, researchers have discovered that they can obtain a suspect's DNA profile by applying the polymerase chain reaction to skin debris present in fingerprints left on forensic evidence (2, 3). In parallel to this advancement, progress has been made in determining the chemical composition of a latent fingerprint using infrared (IR) microspectroscopy and gas chromatography-mass spectrometry (GC-MS) (4-8).Fingerprints primarily consist of material secreted by the eccrine glands located in the palms and fingertips and the sebaceous glands that are located most abundantly on the scalp and face (6). These chemical components include inorganic salts such as iron and sodium, amino acids, and lipids such as fatty acids, wax esters, squalene, and cholesterol (9). IR (7,8) and GC-MS (4-6) studies have examined whether differences in the chemical composition of fingerprints can be used to establish age, gender, and so forth. This information could allow a suspect pool to be reduced even if the fingerprints obtained from a crime scene were smudged or patterns were not matched after being processed in the Integrated Automated Fingerprint Identification System (10).We have adapted a procedure described by Asano et al. (5) and Archer et al. (4) for fingerprint extraction and analysis by GC-MS for use in an undergraduate instrumental analysis course. In the experiment, students collect fingerprint residue samples on glass beads or glass slides, extract the chemical constituents from the residue using chloroform, convert the fatty acids and other components into trimethylsilyl derivatives, and finally, analyze the products using GC-MS. By converting the constituents into less polar, thermally stable materials through silylation, students gain experience in a technique that is frequently required to make samples amenable to GC analysis (11). Furthermore, students can perform a MS library search to identify the components present in their fingerprint residue and then compare their results to demonstrate that more information than just ridge pattern might be obtained from fingerprints found at crime...

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Goforth et al. [Co(C 2 H 8 N 2) 3 ][Bi 2 I 9 ] m1533

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